Sprecher
Beschreibung
We present perturbative QCD predictions for high-momentum particle suppression in very light ion collisions — $^{10}$B $+$ $^{10}$B, $^{6}$Li $+$ $^{6}$Li, $^{4}$He $+$ $^{4}$He, and $^{3}$He $+$ $^{3}$He — comparing calculations with and without medium-induced parton energy loss. Our energy loss model predicts non-trivial suppression across the full range of system sizes at minimum bias, from $^{208}$Pb $+$ $^{208}$Pb down to $^{3}$He $+$ $^{3}$He, and we observe the approximate scaling $R_{AA} \sim A^{1/3}$. We find good agreement with available suppression data from $^{208}$Pb $+$ $^{208}$Pb, $^{197}$Au $+$ $^{197}$Au, $^{129}$Xe $+$ $^{129}$Xe, $^{20}$Ne $+$ $^{20}$Ne, and $^{16}$O $+$ $^{16}$O. Extending our model to unmeasured light-ion systems, we find that tight constraints from deep inelastic scattering on the nuclear parton distribution functions of $^3$He and $^6$Li lead to minimal initial-state modification; these nuclei therefore provide particularly clean environments for isolating final-state partonic energy loss driven by quark-gluon plasma formation in these very small systems.